The instant invention relates to blank fire configurations for automatic pistols. More particularly the instant invention relates to converting a standard automatic pistol to a configuration where the pistol fires blanks in order to simulate live fire for practice and theatrical uses.
Automatic reloading fire arms generally use either gas operated systems or recoil operated systems. Gas operated systems use the pressure of expanding gases produced from burning propellant to operate the reloading mechanism, whereas recoil operated systems use force generated by the recoil of a barrel and/or spent cartridge in relation to the bullet being accelerated from the barrel to operate the reloading mechanism. In either case, the reloading mechanism can be operated by firing blanks after attaching a properly sized restrictor orifice to the muzzle end of the barrel. By doing this, gas pressure is allowed to build up in the barrel and thus drive the reloading mechanism.
Many automatic pistols, including the Colt family of pistols, use a recoil operated system in which the barrel and slide are locked together. The recoil, which results when the bullet is fired, forces the barrel and slide to move as a unit until the barrel unlocks from the slide and stops in the proper position for reloading. The slide continues moving, extracting the spent cartridge and loading a new cartridge into the barrel as it returns to its original position. Firing a blank cartridge in the Colt-type of automatic pistol produces no motion of the barrel and slide due to the fact that firing a blank cartridge produces no recoil. If one attaches a restrictor orifice to the muzzle, pressure builds up in the barrel, but no motion occurs because the barrel and slide are locked together and cannot move independently. Without recoil, the barrel and slide do not unlock.
In order to make the pistol operate with blank fire, one can remove the locking features from the barrel and attach a restrictor orifice to the muzzle. The barrel then remains stationary and the slide is forced rearwardly as gas pressure pushes the spent cartridge from the rear of the barrel. Since the barrel does not move, it is not in proper reloading position. Consequently, the pistol often fails to load the next cartridge, which causes the pistol to jam.
In another approach, the barrel may be modified so that the slide will move a short distance and then contact the barrel and force it rearwardly to the reloading position. However, the amount of gas pressure necessary to operate this type of system is so great that burning gun powder is expelled rearwardly from the barrel when the spent cartridge is extracted. The burning gun powder can strike the shooter in the face, consequently this approach is not acceptable because it is unsafe.
The patent literature contains a number of blank firing attachments, however, these are all systems utilized with automatic rifles or machine guns so as to provide realistic training for troops. The following U.S. patents are exemplary of these approaches: U.S. Pat. Nos. 3,440,924; 4,499,811; 3,137,204; 3,744,370; and 4,261,246. The patent literature also includes kits for modifying automatic pistols for various purposes. For example, U.S. Pat. No. 3,657,959 converts a pistol to fire smaller caliber ammunition, while U.S. Pat. No. 4,580,484 discloses an arrangement for converting a recoil operated automatic pistol to a gas operated automatic pistol. The patent literature does not include references directed to solving the particular problem of converting an automatic pistol which is standard issue to a blank firing pistol for training purposes and theatrical purposes.